Purpose

Differences in pain processing and autonomic function among patients have been implicated the development of chronic pain after surgery. This study was designed to evaluate whether pain and autonomic metrics predict severity of chronic dry eye (DE) symptoms after LASIK, as there is increasing evidence that DE symptoms may be manifestations of persistent post-operative ocular pain.

Methods

Secondary analysis of prospective randomized clinical trial. Patients were treated with either pregabalin or placebo. As no significant differences in DE symptoms were detected by treatment allocation at six months, all participants were grouped together for the present analyses. Subjects were evaluated pre-LASIK with regard to evoked pain sensitivity (utilizing quantitative sensory testing), autonomic metrics and DE and ocular pain symptoms (via validated questionnaires). Measures of DE and ocular pain were assessed post-LASIK, and the Dry Eye Questionnaire 5 (DEQ5) score 6-months after surgery was the primary outcome of interest.

Results

43 individuals were randomized to pregabalin (n = 21) or placebo (n = 22). 42 completed the 6-month visit. Several baseline autonomic metrics correlated with 6-month post-operative DEQ5 scores, including lower systolic (r −0.37, p = 0.02) and diastolic blood pressure (r −0.32, p = 0.04). Ocular pain at 6 months was also negatively correlated with blood pressure (r −0.31, p = 0.047). The presence of painful aftersensations was a significant predictor of chronic DE symptoms at 6 months (mean DEQ5 scores: 8.0 ± 1.9 versus 5.0 ± 5.0, p = 0.009).

Conclusions

Heightened parasympathetic tone and prolonged pain sensitivity measured prior to surgery predicted greater DE symptom severity 6 months after LASIK.

Trial registration

NCT02701764.

中文翻译：

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疼痛敏感性和自主神经系统参数作为 LASIK 术后干眼症状的预测因子

目的

患者之间疼痛处理和自主神经功能的差异与手术后慢性疼痛的发展有关。本研究旨在评估疼痛和自主神经指标是否可以预测 LASIK 术后慢性干眼 (DE) 症状的严重程度，因为越来越多的证据表明 DE 症状可能是术后持续性眼部疼痛的表现。

方法

前瞻性随机临床试验的二次分析。患者接受普瑞巴林或安慰剂治疗。由于六个月时的治疗分配没有检测到 DE 症状的显着差异，因此所有参与者都被分组在一起进行当前的分析。在 LASIK 前对受试者的诱发疼痛敏感性（利用定量感觉测试）、自主指标以及 DE 和眼部疼痛症状（通过经过验证的问卷）进行评估。LASIK 术后评估 DE 和眼痛测量，术后 6 个月的干眼问卷 5 (DEQ5) 评分是主要关注结果。

结果

43 名受试者被随机分配接受普瑞巴林 (n = 21) 或安慰剂 (n = 22)。42人完成了为期6个月的访问。一些基线自主指标与术后 6 个月 DEQ5 评分相关，包括较低的收缩压（r -0.37，p = 0.02）和舒张压（r -0.32，p = 0.04）。6 个月时的眼痛也与血压呈负相关（r -0.31，p = 0.047）。疼痛后感的存在是 6 个月时慢性 DE 症状的重要预测因素（平均 DEQ5 评分：8.0 ± 1.9 与 5.0 ± 5.0，p = 0.009）。

结论

手术前测量的副交感神经张力增强和疼痛敏感性延长预示着 LASIK 术后 6 个月 DE 症状的严重程度更高。

试用注册

NCT02701764。